Use of Frequency Compression in Severe-profound Hearing Loss Adults

Inclusion Criteria: 1. Participants must be over 18 years of age- This study is looking at the use of frequency compression \& its effects of speech perception in adults. 2. No ear surgery that would make it impossible to fit a hearing aid- To ensure limited confounding variables. 3. No history of ear surgery within the last 12 months- To ensure limited confounding variables. 4. No history of ear infection(s) within the last 6 months- To ensure no contraindications and limited confounding variables to testing. 5. No otoscopic abnormality making it impossible to fit a hearing aid- To ensure no contraindications to testing. 6. Bilateral severe-profound hearing impairment with air conduction thresholds \>71dBHL within the frequency range of 250Hz to 4 kHz- To analyse the effects of frequency compression on speech perception within this patient population. 7. Post lingual deafness, with good spoken English- To ensure reliability of speech testing. 8. Previous bilateral digital hearing aid experience (6+ months)- To ensure limited confounding variables. 9. Written consent required. Exclusion Criteria: 1. Participants under the age of 18 years. 2. History of ear surgery making it impossible to fit a hearing aid. 3. History of ear surgery within the last 12 months.